Missing hard drive space after reformat

I reformatted my computer only to find that my C is the usual 15gb but the D is 11gb. when I got the comp D had between 120 and 140gb. I am running windows xp on it. I tried going into manage on my computer hoping to find unallolocated space, but there wasnt any. Thanks in advance for all and any help.

So my computer already came partitioned and the disc automatically partitions it to the way it came. The bios says the hd is 33.8gb. C: used: 9.2gb free: 5.8gb total: 15gb D: used: 34.6kb free: 11.4gb total: 11.4gb. I have another hard drive I could put in which is 160gb and load windows onto there to see if the same problem occurs.

Here is my confusion:
Message #1 in this thread describes a larger HD than what is described in Message #9. If this is the same physical drive, then I have no answer why the bios reports a smaller size by a factor of 3-4 (assumes auto configuragtion).

You are describing an OEM situation. Computer Management > Drive Management should show both drives AND an <unknown partition> containing the system restore files used to recover the system. 7GB for Recovery Partition sounds like a generous amount of pre-loaded applications.

You seem to indicate that the OEM Sytem Restore puts you back to out-of-the-box conditions. For larger sized HDDs, that can result in an extra unallocated partition OR the extra space is assigned to existing partitions. The Recovery Partition should always be a fixed size.

Here is one link about HD size does matter. Converting between binary & decimal versus the advertised HD size causes some of the confusion.

Pre- SP1 for XP cannot use disk capacity above 137GB ( de-rated to 128GB because of the above),

found the problem. Told my parents about the situation and they decided to get a new comp rather then a new hard drive. so i was in the process of stripping off anything that would be usable I found out that 2 or 3 of the pins had been damaged. I believe this to be the problem. thanks to everyone who tried to help me.